1. Field of the Invention
The present invention generally relates to positive feed drills. More particularly, certain features, aspects and advantages of the present invention relate air motor positive feed drills.
2. Description of the Related Art
Positive feed drills are used to produce accurately placed and accurately dimensioned holes in work pieces. One application of this type of drill is in the aircraft industry where the holes are formed in materials that can be difficult to cut. To overcome issues relating to cutting through such materials, drilling/cutter lubricant can be delivered to the cutting surface to, among other things, provide lubrication, remove heat, and/or remove the cutting chips from the hole.
A common way to deliver drilling lubricant is by spraying a mist of air and drilling lubricant through the cutting tool via longitudinal holes that extend through the cutter from its shank to its tip. In this way, the atomized spray of cutting fluid is delivered directly to the cutting surface. After the point of the cutter has broken through the backside of the work piece, the cutter can continue to rotate as the drill is pulled back out of the hole. This can prevent the tool from becoming stuck in the hole, and also can improve the quality of the finished hole.